The festival at the Azhagar Temple near Madurai is celebrated every year in the month of Vaikasi. The deity in the temple is Lord Vishnu in the form of Kallazhagar. The temple is situated 21 kms from Madurai city.
Legend has it that the sage Suthapas was bathing in the river Nupura Gangai one day and did not hear the Maharishi Durvasa coming his way. Durvasa, known for his fiery and short temper, cursed the sage and turned him into a frog, only to be redeemed by the Lord Sundarajar.
The sage Suthapas then performed penance by the banks of the river Vaigai until the Lord, also known as Kallazhagar, relieved him. The sage is also known as Mandoonga Munivar because of his frog form.